Hi Cuckoo, Have read what you said about a friend helping you inject your pigs, and presume it's something like Ivomec that you'll be using.
However, if you're wanting to worm them in future and still have a problem with injecting, then you can get Panacur liquid from BATA at Carlton, near Snaith. The smallest quantity is a lot less than £45, or failing that, if you PM me I can sell you the ammount you need as I use the 10% solution for all my animals - cattle, sheep, dogs, hens, horses, donkeys, mule, husband... (only joking there).
I live near Snaith, which I presume is not a million miles away from you